Methods for Depositing a Film on a Backside of a Substrate

Abstract

A method for processing a substrate in a plasma processing system having a showerhead and a shower-pedestal oriented below the showerhead is provided. The method includes supporting the substrate between the showerhead and the shower-pedestal. The substrate is supported to be spaced apart from the shower-pedestal and the shower head. The method includes flowing a process gas out of the shower-pedestal in a direction that is toward a backside of the substrate, and flowing an inert gas out of the showerhead in a direction that is toward a topside of the substrate. The method includes generating a plasma, using the process gas, between the shower-pedestal and the backside of the substrate. The plasma is configured to deposit a film on said backside of the substrate and the inert gas is configured to prevent or reduce deposition on said topside of the substrate.

1 . A method for processing a substrate in a plasma processing system having a showerhead and a shower-pedestal oriented below the showerhead, comprising,
 providing a carrier ring between the showerhead and the shower-pedestal, the carrier ring is configured to support the substrate;   flowing a process gas out of the shower-pedestal in a direction that is toward a backside of the substrate;   applying power to an electrode of the plasma processing system, the power is configured to produce a plasma in a region between a top surface of the shower-pedestal and the backside of the substrate, the plasma being configured to produce a material layer from the process gas that is deposited onto the backside of the substrate; and   flowing an inert gas out of the showerhead in a direction that is toward a topside of the substrate, the flowing of the inert gas is configured to proceed while the flowing of the process gas, such that the process gas is purged from the topside of the substrate using the inert gas to prevent deposition on said topside while the material layer is deposited onto the backside of the substrate.   
     
     
         2 . The method of  claim 1 , wherein the shower-pedestal includes a plurality of holes that define orifices, the orifices configured to,
 direct the flow of process gas perpendicular to a surface of the shower-pedestal in a direction that is toward the backside of the substrate in a center region that extends proximate to an edge of shower-pedestal; and   direct the flow of process gas at an angle that is away from the center region using a plurality of orifices arranged in the edge of the shower-pedestal.   
     
     
         3 . The method of  claim 1 , wherein the shower-pedestal includes a plurality of zones for delivering the process gas a different flow rates or applying a different process gas to each of the plurality of zones, wherein the different process gas is configured to define different material deposition zones on the backside of the substrate. 
     
     
         4 . The method of  claim 1 , wherein the a top surface of the carrier ring is placed to be at least within 0.5 mm from a top surface of the showerhead and spaced apart from the shower-pedestal. 
     
     
         5 . The method of  claim 1 , wherein the carrier ring is supported by a plurality of spacers, such that the carrier ring is placed proximate to the showerhead during the flowing of process gas and a process space is defined between backside of the substrate and the top surface of the shower-pedestal. 
     
     
         6 . The method of  claim 1 , wherein a spider forks are used to lift the carrier ring at a separation distance from the top surface of the shower-pedestal while the flowing of the process gas is performed. 
     
     
         7 . The method of  claim 1 , wherein the power is applied to one of the showerhead or the shower-pedestal. 
     
     
         8 . A method for processing a substrate in a plasma processing system having a showerhead and a shower-pedestal oriented below the showerhead, comprising,
 supporting the substrate between the showerhead and the shower-pedestal, wherein the substrate is supported to be spaced apart from the shower-pedestal and the shower head;   flowing a process gas out of the shower-pedestal in a direction that is toward a backside of the substrate;   flowing an inert gas out of the showerhead in a direction that is toward a topside of the substrate;   generating a plasma, using the process gas, between the shower-pedestal and the backside of the substrate, the plasma is configured to deposit a film on said backside of the substrate and the inert gas is configured to prevent deposition on said topside of the substrate.   
     
     
         9 . The method of  claim 8 , wherein said inert gas assists in purging said process gas from between the shower head and said topside of the substrate. 
     
     
         10 . The method of  claim 8 , wherein supporting the substrate includes,
 holding the substrate in a carrier ring, the carrier ring being elevated above the shower-pedestal.   
     
     
         11 . The method of  claim 10 , further comprising,
 raising the carrier ring to be elevated above the shower-pedestal using a plurality of spacers.   
     
     
         12 . The method of  claim 10 , further comprising,
 raising the carrier ring to be elevated above the shower-pedestal using spider forks.   
     
     
         13 . The method of  claim 8 , wherein the shower-pedestal includes a plurality of orifices, the method comprising,
 flowing said process gas perpendicular to a surface of the shower-pedestal in a direction that is toward the backside of the substrate in a center region that extends proximate to an edge of shower-pedestal; and   flowing said process gas at an angle that is away from the center region using a plurality of orifices arranged in the edge of the shower-pedestal.   
     
     
         14 . The method of  claim 8 , further comprising,
 flowing said process gas in a plurality of zones, wherein each zone is controlled to define a profile of said film on the backside of the substrate.   
     
     
         15 . The method of  claim 8 , further comprising,
 placing the topside of the surface at a separation that is at least within 0.5 mm from a top surface of the showerhead.   
     
     
         16 . The method of  claim 8 , further comprising,
 applying power to one of the showerhead or the shower-pedestal to strike said plasma.